Re: Correct fuel/oil ratio for mid 1950’s Johnson

[frankr]

quote dshanks:

Thanks guys. 16:1 it is. Yes, the motor does smoke even at 24:1; especially while warming up. Guess I need to find a local source for biodegradable oil.

I’m surprised that one official manual says 24:1 when the official Johnson service manual I found (published by OMC) says 16:1. Maybe OMC engineers eventually discovered less oil was really needed?

Even at 24:1, the plugs (J6C) seem oily. Is that normal?

Funny about the bugs. My father, the motor’s 2nd owner, was an entomologist. 😉

I can show you an official Johnson service publication that says 50:1 is ok. But that is ONLY if Johnson oil is used. Now, that original Johnson oil is obsolete, and is today’s oil the same thing? Good question, huh? I guess you decide. But for me, on that motor with it’s known wrist pin problem, I’d use at least 24:1 or more.

Sure, the plugs will be oily. Especially after running at low speeds. That’s just the way it is.

You suggested that OMC engineers discovered that less oil was really needed (?). Matter of fact, I heard that directly from one of them at a service clinic when 50:1 was introduced.